The present invention generally relates to semiconductor manufacturing and more particularly to the formation of middle-of-the-line (MOL) contacts having a bilayer oxygen getter film.
In semiconductor technologies, tungsten (W) is typically used as a middle-of-the-line (MOL) contact material mainly because of its relatively low resistance, less stress, and electro-migration properties. A MOL contact may be a conductive stud working as an interface between contact areas of an active semiconductor device (or integrated circuit), which may be referred to as front-end-of-the-line (FEOL), and its overlying interconnects structures, which may be referred to as back-end-of-the-line (BEOL). Contact areas of an active semiconductor device may be made of, for example, a silicide material. MOL contacts are usually formed in a layer of dielectric material deposited on top of the active semiconductor device. A plurality of openings may be formed in the layer of dielectric material to form the MOL contacts. The MOL contacts may extend to surfaces of the contact areas of underlying semiconductor devices.